A very scarce, original Civil War army headquarters badge for the 23rd Army Corps. As we all know, there are hundreds of fake badges out there for every real one. Here's a real one.
Shield shape with bullion border and wool centers in red, white and blue.
Phillips quotes letters indicating the badge was established in the winter of 1863-64, and was worn throughout the Atlanta campaign, being officially adopted in September 1864 in an order that tried to produce some uniformity. Capt. J.M. Marshall, who had been Chief of Staff to Gen. Schofield recalled the HQ badge having blue in the upper right and white at the bottom, as this badge does, though the form finally adopted reversed that, which is a nice indicator that this badge is likely the earlier configuration.
About 2 1/2 by 2 1/4 inches. As the wearer was an officer on duty at corps headquarters this would be worn on the side of the hat.
Shipping $10 insured. NY addresses add sales tax.